Electrothermal switch.



' J. ERIGKSON.

BLEGTROTHERMAL SWITCH. APPLICATION FILED MAY 9, 1906.

1,009,834, Patented Nov. 28,1911.

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UNITED STATES PATENT OFFICE.

JOHN ERICKSON, OF CHICAGO, ILLINOIS, ASSIGNOR,IBY MESN E ASSIGNMENTS, TO FIRST TRUST AND SAVINGS BANK, TRUSTEE, OF CHICAGO, ILLINOIS.

ELEcrRo'rHEnMAL SWITCH.

To all whom "it may concern:

Be it known that I, JoI-IN ERICKSON, a

citizen of the United States of America,

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and resident of Chicago, Cook county, Illinois, have invented a certain new and useful Improvement in Electrothermal Switches, of which the following is a specification.

My invention relates to electro thermal switches or circuit-controlling devices, such, for example, as those commonly known as heat-coils, devices of this character being particularly adapted for use in protecting telephone or other electrical apparatus against the injurious elfects of abnormal currents, especially sneak currents.

Generally stated, the object of my invention is the provision of an improved and highly efiicient electrothermal switch or circuit-controller of the above general char acter.

Special objects of my invention are the provision of an improved construct-ion and arrangement for permitting the switch to be reset or restored without the necessity of supplying any new parts; the provision of such a construction and arrangement as will permit the switch to be reset or restored several times without employing self-soldering features or other similar expedients; the provision of means whereby a piece of solder or other fusible material can be melted or fused a little each time that the switch responds to an abnormaL current, and then readjusted each time until it is entirely used up; and the provision of certain combinations and details of construction tending to increase the general efliciency of an electro-thermal switch or heat-coil of this particular character.

To the foregoing and other useful ends, my invention consists in matters hereinafter set forth and claimed.

In the accompanying drawings, Figure 1 is a perspective of an electro-thermal switch or heat-coil embodying the principles of my invention. Fig. 2 is a side elevation showing certain portions in section, and illustrating the switch or heat-coil in an operated or open condition. Fig. 3 is an enlarged section of the heat-generating portion of the device. Fig. 4 is an enlarged plan view of the heat responsive portion of Specification of Letters Patent.

Patented Nov. 28; 1911.

Application filed May 9, 1906. Serial No. 315,938.

end of said spring a disk or solder C is mounted, and held in place by a screw or pivot c. The bracket or support B carries a metal pin 6. A resistance-coil 5 is mounted upon the said pin and inclosed by a piece of insulation E5 A circuit wire 5 can be secured to one terminal of the said resistance-coiLand the other terminal of said coil can be electrically connected with the said pin. It will be seen that the said pin and the s ring a extend horizontally to-- ward each ot er. Preferably, both the pin and the spring are insulated from their respective supports.

Normally the parts are in the positions shown in Fig. 1. such condition the switch afiords a eircuit'from the spring a to the solder disk C, thence through the pin 5 to the resistance-coil 5 and then through the balance of the circuit in which the device may be included; or, of course, the current may be caused to travel in the opposite direction. Should the current become abnormally strong, or should a sneak current show its presence in the circuit, theheat generated by the resistancepoil 5 will heat the pin 5. This heat will then be communicated to the portion of the disk C in contact with the end of the pin, with the result that the solder will immediately melt at this point, and permit the spring to assume the position shown in Fig. 2-that is to say, the melting of the solder will produce a rupture in the circuit. The attendant can then? press the spring a back into its normal position, and by then slightly rotating the disk.@ the parts will regain their normal or original positions. In order to facilitate the setting of the device for the'first time, before it is subject to current, a notch may be cut in the periphery of the disk 0. It will be understood. however, that the spring of the parts is sufficient to permit the disk 0 to be swung slightly to one side and then allowed to press upwardly against the end of the pin 5.

With this arrangement, the device can be reset over and over again until the marginal or peripheral portions of the disk 0 are .5 completely used up. After this a new disk of solder can be substituted for the old or the worn out one, and the operation can then be repeated until the new piece of solder is completely used up. In this way, I provide an electro-thermal switch or heatcoil which can be reset as soon as it is sprung or opened by abnormal current, and this resetting is accomplished without any self-soldering or other equivalent expedient.

In Fig. two springs D and E are provided and held normally in contact with each other, the spring D being-provided with the solder-disk C. Also, in this case, the pin which engages the solder may or may not be in the circuit, as desired. With these exceptions, the construction is the same as in the other figures. With the arrangement shown in Fig. 5 the circuit simply includes the two switch-springs and the resistancecoil, and thus neither the solder nor the pin are in the circuit. when the solder melts the two springs are separated, and the circuit is opened. It will be seen, therefore, that I provide a piece of solder or other fusible material which mechanically holds the switch in a closed condition, and which can be melted a little each time the switch responds to abnormal current, and adjusted or turned a little each time until the marginal or peripheral portions thereof are completely used up. In this way, the device can be reset without supplying any new or fresh parts, and without resorting to any self-soldering action.

I do not limit myself to the exact construction shown and described.

\Vhat I claim as my invention is 1. An electro-thermal switch comprising a resistance for generating the heat, a metallic member to be heated by said resistance, a piece of fusible material normally engaging said member to be heated, and means for mounting said piece of fusible material for movement to bring fresh portions thereof into contact with said member to be heated, after each operation of the switch.

2. An electro-thermal switch comprising a resistance for generating the heat, a member to be heated by said resistance, and a rotatable disk of solder normally engaging said member to be heated, said disk rotatable to bring fresh portions thereof into contact with said member, after each operation of the switch.

3. An electro-thermal switch comprising a resistance for generating the heat, a member to be heated by said resistance, a spring, a disk of solder rotatably mounted upon the end of said spring, held normally in engagement with the end of said pin, adapted to be rotated to bring fresh portions thereof into contact with the pin.

4. An electro-thermal switch comprising a resistance for generating the heat, a member to be heated by said resistance, a piece of fusible material, spring means for holding the fusible material in engagement with the said member, and means for mounting said fusible material for movement to bring fresh portions thereof into contact with said member, after each operation of the switch.

5. In a device of the class specified, the combination of a normally closed circuit, a heat-generating resistance in said circuit, a member to be heated, a piece of fusible material normally engaging said member to mechanically hold the circuit closed, and means for mounting said piece of fusible material for movement to bring fresh portions thereof into contact with said member, after each operation of the switch.

6. In a device of the class specified, the combination of the support A, the spring a mounted thereon, the disk of solder C rotatably mounted on the end of said spring, the support B, the metallic pin I) mounted upon said last-mentioned support, and the resistance-coil b mounted upon said pin, said disk of solder C normally engaging the under side of the end of said pin, adapted also to be rotated to bring fresh portions thereof into contact with said pin, substantially as and for the purpose set forth.

7. An electro-thermal switchcomprising a piece of fusible material, a projection engaging the same, means for heating said projection, and means for supporting'and moving the fusible material when the heat at said projection rises to the melting or fusing-point.

8. An electro-thermal switch comprising a rotatable disk of fusible material, a projection engaging said disk at one side of the edge thereof, means for heat-ing said projection, and means for moving said disk bodily when the heat at said projection rises to the melting or fusing point.

9. In a device of the character specified, a switch spring, a contact adapted to be engaged by said switch spring to close the circuit, fusible material carried by said switch spring, a metallic projection engaging said fusible material to keep the switch closed, and means for heating said projection by means of an electric current.

10. In a device of the class specified, a disk of fusible material, and means for supporting and moving said disk bodily when melted or fused at its periphery, as set forth.

11. In a device of the class specified, a substantially fiat piece of fusible material, means for mounting said piece of fusible material, a projection engaging an edge portion of said material, means for heating said projection to fuse the said material, means for causingrelative movement between the said material and the said projection When the material is thus fused and a circuit controlled by the engagement of said material by the said projection, said material being adjustable to bring different portions thereof into'engagement With said projection, whereby the device is operable a number of times before the piece of fusible material is entirely used up,

Signed by me at Chicago, Cook county, Illinois, this 1st day of May, 1906.

JOHN ERIGKSON.

Witnesses:

EDWARD D. FALES', CHARLES J. ERICKSON. 

